Conventionally, there is known a plasma processing apparatus for performing plasma treatment on a target object such as a wafer or the like by using a plasma. The plasma processing apparatus includes a mounting table serving as an electrode and configured to hold the target object. The mounting table is provided in a processing chamber capable of forming a vacuum space. The plasma processing apparatus performs the plasma treatment on the target object mounted on the mounting table by applying a predetermined high frequency power to the mounting table. Through holes into which lifter pins are inserted are formed in the mounting table. In the plasma processing apparatus, when the target object needs to be transferred, the lifter pins project from the through holes and separate the target object from the mounting table while supporting a backside of the target object. The lifter pins are made of an insulating material in order to suppress occurrence of abnormal discharge caused by exposure to a plasma. Lower portions of the lifter pins are made of a conductive material (see, e.g., Japanese Patent Application Publication No. 2000-195935).
Recently, in the plasma processing apparatus, a voltage of a high frequency power that is applied to the mounting table to perform the plasma treatment is increased. When the voltage of the high frequency power applied to the mounting table is increased, the abnormal discharge may occur at the through holes into which the lifter pins are inserted. In the plasma processing apparatus, the abnormal discharge at the through holes leads to deterioration of a quality of the target object. This may result in deterioration of a yield.